Niobium sintered body for capacitor and process for producing same

Abstract

A niobium sintered body for a capacitor, which exhibits an LC value of not larger than 300 μA/g as measured after an electrolytic oxide film is formed thereon. The sintered body preferably exhibits a product (CV) [i.e., a product of capacity (C) with electrolysis voltage (V)] of at least 40,000 μF·V/g. The sintered body is produced by sintering a niobium powder containing at least one niobium compound selected from niobium nitride, niobium carbide and niobium boride. A capacitor manufactured from the sintered body has a large capacity per unit weight and good leak current characteristics. Especially, a sintered body made of a niobium powder having a large average degree of roundness has a relatively large porosity and a good packed density, and a capacitor manufactured from this sintered body has a large capacity and good withstand voltage characteristics.

Dependencies are inferred from the claim text.